Network-based communication, and in particular the Internet, facilitates rapid and easy access to sources of information. This access to information is utilized by all Internet users, including researchers and authors of technical literature. The sources of information accessed include printed articles that are posted or made accessible through the Internet and articles or documents that are strictly electronic publications. When these Internet-accessible sources are referenced in a document or publication, the reference includes a written link that can be used to access the document. In addition, when the publication containing the Internet-accessible source is viewed in an electronic format, the written links are also provided in hypertext format, enabling a user to simply click on the hyperlink to be taken to the referenced source. When using the hypertext link format, the actual text of the reference does not have to include the actual written link. These hypertext links can be used within various types of publications including within word processor documents.
Although network-based communications provide rapid and easy sharing of information, this ease of exchange also creates an environment that is fluid and capable of rapid change. Sources of information can be modified or moved to different locations across the network. In addition, various forms and versions of the same source of information can be propagated across the network. In addition to issues covering the actual content of the information sources, the network itself can experience changes and failures. For example nodes within the network can experience temporary or permanent failures, inhibiting access to sources of information. Once a link to a source is created within a document, changes to the link or to the information contained in the source associated with that link affect the veracity and usability of the original document. The authors and users of these documents want to ensure the veracity of the citations and links within the document.
Often, articles appearing in scientific journals are created as word processor documents containing a large number of references that are embedded in the text of the articles, provided in footnotes or provided in a list of references at the end of the articles. All of these reference lists can contain webpage uniform resource locators (URLs) that need to be checked for viability and status both before the article is published, for example typeset and published, and during the period of time that the article is available in an electronic format. Therefore, systems and methods are desired to check the links embedded in documents and to visually indicate link characteristics within the document.